Blasting-cap and carrier therefor.



J. R. POWELL. BLASTING GAP AND CARRIER THEREFOR.

APPLICATION FILED MAY 26, 1913.

v Patented Dec. 16, 1913.

2 SHEETS-SHEET 1.

.NAM/MN v WITNESSES ATTORNEY J. R. POWELL. BLASTING CAP AND GARRIER THEREFOR.

APPLIGATION FILED MAY 26, 1913.

Patented Dec. 16, 1913.

2 SHEETS-SHEET 2.

NYN 0 7/ 11x WITNESSES ATTORNEY miran srATEs `imiiran'r ormon.

YJOHN R. rowELI., or PLYMOUTH, PENNSYLVANLA.

BLASTING-CAP AND CARRIER THEREFOR.

incentive.

` of elongated copper tubes closed at one end and containing a quantity of fulminate of mercury, the caps being usually about an inch andv a half, `more or less, in length.

Under the ordinary practice these caps must be attached to the fuses and it is customary for a miner to carry a quantity of caps and 'when ready to set o a blast a suitable length of fuse is cut and introduced into the open end of the cap which is left open for such a purpose, and then made fast to the fuse in any convenient way, it being not infrequent for a minerpto bite the cap on to the fuse, and this has frequently resulted in serious and fatal accidents. Again, the dynamite or other explosive employed is often located at the end of a borewhich may be four or more feet in depth, and consequently under the ordinary practice the fuses must be long enough to reach to the accessible end of the bore, wherefore the cost of the cap and fuse is considerable and is borne by the miner.

In order to savel the long length of fuse an iron blasting tube may be employed and is introduced into the bore after the charge is in place, and the cap is located at the end of the tube adjacent to the charge, whereupon the cap is exploded by the use of a squib which may be introduced into the accessible end of the tube and lighted and after a time powder carried by the squib becomes ignited and causes the squib to travel to the inner end of the tube where it will ignite the cap and the explosion of the latter causes the explosion of the dynamite or other charge. The blasting tube method of providing a way for the squib to traverse is advantageous, and the present invent-ion has to do with a cap structure which may be adapted to the tube in a manner which will prevent displacement of the cap, and

the arrangement 1sV such that the cap is far Speccation of Letters Patent.

Patented Dec. 16, 1913.

Application led May 26, 1913. Serial No. 769,919.

more liable to be ignited than are the caps as ordinarily used under like circumstances.

The invention further contemplates a cap and carrier or support therefor which may replace the blasting tube, and at the same time may be so arranged as to provide for a way or course for the squib.

In accordance with one form of the present invention there is provided a cap having an exterior wrapping, or sheath, which may or may not be longer than the cap, and which may or may not have a charge of powder therein in addition to the usual fulminate of mercury in the cap or detonator. The outer covering or sheath for the cap is made tapering at theend remote from the active or fulminate end of t-he cap, so as to wedge in the inner end of the blasting tube when used, or in one end of a short tube which may act as a carrier for t-he cap, and this short tube may have applied thereto when introduced into the drill hole, or may have permanently applied thereto, an eX- terior bushing serving as an inner abutment for tamping material, and protecting the cap from injury during tamping. When the short tube is used a blunt needle rod is employed with the thinner end introduced into the outer end of the tube to thereby constitute a core around which the tamping material may be forced, so that on the withdrawal of the needle rod.there is left a small bore or passageway along which the squib may travel to the short tube and there set re to the fulminate in the cap or to a powder charge carried by the outer sheath of the cap.

The invention will be best understood from a consideration of the following detailed description, taken in connection with the accompanying drawings forming a part ofthis specification, with the further iinof a drill hole presumed to be made in the rock or other material to be blasted and showing a cartridge or charge, a cap, a blasting tube, and a squibin place. Fig. 2

- where the latter is a similar view of the inner end of the bore showing the short-tube carrier for aV cap and its sheath and also showing the smaller blunt end of a needle bar in position to act as a core for tamping material.

Fig. 3 is a view similar to Fig. l but show- A ing the construction illustrated in Fig. 2 with the tamping material in place. Fig.

4 is a View of a needle bar modified for" use in connection with the present invention. Fig. 5 isa displayed view of a sheet of material from which the sheath of a cap structure may be made. Fig. 6 is a view of such a sheath.

Referring to the drawings, there is shown a cap 1 which may be of the character usually employed in blasting, and this cap is indicated as containing a mass 2 of -detonating material which is customarily fulminate of mercury. The cap is permanently closed at one end, as indicated at 3, and is open at the other end, .as shown at 4 in Fig. l. Such cap is ordinarily applied to one end of a length of fuse long enough to reach from the accessible end of a drill hole in the rock or coal or other material and indicated at 5 in the drawings, to the cap 1, the active end of which latter is introduced into one end of a casing 6 representing the casing of a charge indicated at 7, which latter may be dynamite or permissible powder or any other suitable explosive. Of course, ordinary black powder may be used, but the use of such powder is objectionable, especially in gaseous mines, because the powder makes a great deal of flame, while dynamite and permissible powder do not have this objectionable characteristic.

In accordance with the present invention the cap 1 is inclosed in a sheath 8 which may be of substantially the same length as the cap, as in theshowing of Fig. l, or may be considerably longer than the cap as indicated in Fig. 2, and in the latter case the sheath where it projects beyond the cap may be filled with powder, indicated at 9, this powder readily igniting under circumstances to be described, and so setting off the detonating material within the cap.

Considering the arrangement shown in Fig. l, there is provided a blasting tube 10 of an external diameter to enter one end of the casing 6 of the dynamite or other cartridge after the usual filling at that end ofthe cartridge has been displaced to permit the introduction of the detonating cap. This tube 10 is made long enough to extend to the outer end of the drill hole 5, so as to be readily accessible.

lt has been proposed heretofore to use a blasting tube such as indicated at 10 and to have this tube partially inclose the cap l enters the charge, but the cap does not snugly fit the tube and consequently there is a liability, especially when the hole 5 inclines, for the cap to slip down the tube toward the outer end and possibly become lodged therein at a considerable distance from the charge to be exploded. Under these circumstances there is no certainty but that such a contingency may happen at any time and the cap be exploded at so great a distance from the charge as to fai-l to ignite the latter. To overcome this objectionable feature the sheath 8 is provided, making the commercial cap of an exterior diameter which will permit it to be lodged in one end of the tube 10 in a manner whereby it cannot possibly move into the tube and when once positioned with respect to the charge will remain in such position until exploded. To bring about this arrangement the cap has wound thereon a sheet 1l of paper shown separately in Fig. 5, which sheet is long enough in one direction to wrap a suflicient number of times about the cap to bring the external diameter of the sheath 8 made of the paper sheet a little greater than the internal diameter of the tube 10. The web 11 which may be made of waterproof paper or other suitable material, is not of the same width throughout, but has cut away portions near the ends forming bevel edges 12, 13, respectively, so that when the web is wound around the cap one end of the sheath is of lesser external diameter than the other, giving to this end of the sheath a taper, the smallest diameter of which is less than the internal diameter of the corresponding end of the tube 10, so as to readily enter thereinto, but that portion of the end of the sheath not including the beveled edges l2 and 13 is of full diameter which is too great to enter the tube. Because of this the sheath will tightly wedge in the tube against any possibility of accidental displacement.

Considering the parts described with reference to Fig. 1 as all properly located in the hole 5, and the latter filled with tamping material if necessary, a squib 14 is introduced into the accessible end of the pipe and lighted, and this squib is of a character which will burn slowly for a sufficient length of time to permit the miners to reach a point of safety. A portion of the squib is filled with powder which will burn in a manner to drive the squib lengthwise of the tube 10 and to and into the open end 4 of the cap l, setting fire to the detonating material 2 which is of a character to explode violently and so ignite the charge.

There are certain objectionable features to the employment of the tube 10 which are wholly overcome by the structure shown in Figs. 2, 8 and 4. In this arrangement the cap is inclosed in one end of a sheath 8fL which may be considerably longer than the cap, say, twice as long, but is constructed with a taperingend thesame as the sheath 8 shown in Figs. 1 andf 6.,- That end of the sheath 8a remote from the cap is-iilled with powder 9 as already describedyso that such powder may be ignited, and lis in fact more readily ignited under the contingencies of use than `isthe fulminate 2. There is also provided a tube- 15 which may beseveral inches in length andlonger than the elongated sheath 8a,'whil`e the taper end of the sheath 8a is so related to the tube 15` as to enter one end o f"`thelatber with the untapered or Vcylindrical end of the sheath 8a exterior thereto, the external diameter of the cylindrical portion of-the sheath 8iL being greater-than the internal diameter of the tube15.

Applied to the exterior of the tube 15 is a bushing 16 preferably of asbestos, and this bushing is of an external diameter such asto l i'it closely in the drill hole 5. The bushing 16 may be" considerably less in length'than the length of thertube 15 and is designed to act as an abutment for tamping material, such as indicated at 17 in Fig. 8.

In the mines are implements known as needle rods, VVand it is the purpose of the present invention to utilize such needle rods by cutting off their extreme taper endsuntil there is roduced a blunt end of about onefourth oi) an inch in. diameter. Such a needle rod so modified is indicated at 18 in Fig. 4 and a portion of such a rod is shown at 18 in Fig. 2. The tube 15 and the taper end of the rod 18 are sorelated that the rod 18 will `enter the tube 15 for a suitable distance but less than the distance necessary to reach the sheath 8a, sothat there is no chance of friction setting the powder 9 atire. Therod 18 is utilized as a core about which the tamping material 17 may be packed, and this tamping material reaches to the bushing 16, which latter protects the cap from either contact with or displacement bythe tamping material. Such tamping material may consist of clay or earth or coal-dust or whatever may be accessible for the purpose, while the bushing 16 presents a refractory and dense abut- A V Y Y i Y I ment far superior to any material heretofore used, and protects the cap from chance sparks. When the tamping material 17 has set the rod 18 is withdrawn and a bore or passage 19 is left leading from the exterior of the drill hole 5 to the outer end of the tube 15. The passage 19 shown in Fig. 8 is comparatively smooth on the interior due to the rod 18, anda squib 14 maybe introduced into this bore 19 and on being ignited will travel to the tube 15 and readily enter the same until it reaches the powder 9 which becomes ignited and quickly carries the flame to the detonating material Q'and causes the explosion as before. Y

With the arrangement shown in Figs. 2

eliminated and not only isthe cap easily and accurately placed, but it cannot become displaced before the explosion.

The present invention provides a meansV contributing very markedly to the safety of the miners by eliminating certain dangerous practices and conditions which have heretofore prevailed.

What is claimed is 1. A blasting cap provided with an external substantially inelastic sheath Asnugly fitting4 vthe cap throughout and having t-he end remote from the active end externally tapering.

2. A blasting cap provided with an externalv sheath longer than the cap and externally tapering at the end remote from the active end of the cap, the tapering end having a filling of powder.

3. A blasting cap providedV with an external sheath having lone end externally tapering, sheath of al diameter to receive and snugly vand a tubular carrier for the wedge thetapered end of the sheath when p introduced into one end of the carrier.

4. A blasting cap provided with an external and substantially inelastic sheath 1 having the end remote from the active end of the cap externally tapering, in combination withV a tube having one end of a diameter to cause the tapering end of the sheath, when introduced into the tube, to wedge therein. n'

5. A blasting cap provided with a sheath having one end externally tapering, and an elongated tube having one end of an internal diameter to receive and cause the tapering end of the sheath to wedge therein and less than the external diameter of the larger end of the sheath.

6. A blasting cap provided with a sheath longer than the cap and having the end remote from the active end of the cap filled with powder and externally tapering, and a carrier for the cap in the form of a tube of an internal diameter to receive the tapering end of the sheath and less than the external diameter of the larger end of the sheath.

7 A blasting cap provided with a sheath longer than the cap and having the end remote from the active end of the cap filled with powder and externally tapering, and a carrier for the cap in the form of a tube of an internal diameter to receive the tapering end of the sheath and less than the external diameter of the larger end of the sheath, and an external bushing for the tube of a diameter substantially that of the drill hole into which the cap is to be introduced.

8. A blasting cao provided with a sheath longer than the cap and having the end remote from the active end ofthe cap filled Y Y of an internal diameter to receive the tapering end of the sheath and less than the external diameter of the larger end or" the sheath, and an external bushing for the l tube of a diameter substantially that of the drill hole into which the cap is to be in` troduced, said bushing being made fast to the end of the tube into which the cap sheath is introduced.

9. A blasting cap provided With an external sheath and a carrier therefor having a bore of greater internal diameter than that of the cap and less than that of the sheath and related to the sheath to snugly receive and Wedge that end of the sheath remote from the active end of the cap.

10. A blasting cap provided With a sheath, a carrier in the form of a tube related to the sheath to receive one end thereof snugly, and a bushing for the carrier adapted to the exterior thereof and to the drill hole into Which the cap and carrier are to be introduced.

11. A means for applying blasting caps to charges when lodged in the inner end of a drill hole, comprising a sheath for the cap, a tubular carrier related to the sheath to snugly receive one end thereof With the cap end of the sheath projecting from theV carrier7 a bushing adapted to the exterior of the carrier, and a core rod having one end tapering to enter the end ofthe carrier remote from that entered by the sheath.

12. A blasting cap having an external sheath prolonged beyond one end of the cap and there filled With powder, and an inelastic tubular member related to the cap and sheath yto receive and lodge them tightly at one end of the tubular member against Vaccidental displacement.

13. v A means for applying blasting caps to charges When lodged in the inner end of a drill hole, comprising a sheath for the cap, atubular carrier related to the sheath to snugly receive one end .thereof With the cap end of the sheath vprojecting from the carrier, and a core rodv having one end tapering to enter the end of the carrier remote from that entered by the sheath.

14. A blasting cap provided with an ex ternal sheath comprising a sheet oi suitable material Wider at one end than the other and Wound upon itself in the direction of its Width to provide a tube externally tapering at olie end.

In testimony that I claim the foregoing as my own, I have hereto aixedmy signature in the presence of tWo Witnesses.

,- JOHN R. POWELL.

Witnesses:

JOHN H. SIGGERS, EDITH L. BROWN.

Copies of this patent may 'be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. C. 

